Eurycotis pluto Hebard 1920

Eurycotis pluto new species (Plate V, figure 13.)
The present uniform shining blackish insect is the largest yet described species of the genus. 1 1 belongs to the group of relatively slender forms having lateral pad-like tegmina.
The species is very closely related to E. biolleyi Rehn, differing in its great size and relatively narrower form, the greatest abdominal width being contained distinctly over twice in the body length, approximately twice in biolleyi.
Relationship with the Brazilian E. manni Rehn also exists; comparison with the male t>'pe shows that species to be absolutely black, decidedly smaller, with caudal metatarsi proportionately very decidedly shorter.
Type. — 9 ; Porto Bello, Panama. March 2, 191 1. (A. Busck.) [United States National Museum.]
Size extremely large; form elliptical, depressed, relatively slender for the genus. Surface polished. Head with occiput transversely evenly convex, interocular space very broad, slightly broader than width between antennal sockets; ocellar spots distinct; antennae elongate, not equal to body length. Maxillary palpi with fifth joint not strongly enlarged, subequal in length to fourth; fourth about threequarters as long as third joint.
Pronotum of the usual form for the genus; surface smoothly convex, briefly and suddenly deflexed on either side of the head; caudal margin straight laterad, showing a very feeble broad convexity mesad. Mesonotum with caudal margin much as that of pronotum. Metanotum with latero-caudal angles slightly but appreciably produced, sharply rectangulate, the lateral portions of the caudal margin resultantly distinctly concave. Tegmina lateral, slightly surpassing the caudal margin of the mesonotum, length of exposed portion one and one-half times greatest width; costal margin very feebly convex, weakly cingulate, apex subrectangulate and rather sharply rounded; sutural and distal margins regularly convex, the angle formed by their juncture obtuse and broadly rounded. Wings absent.
Abdomen elongate, scarcely broader than thorax and with surface very slightly less convex; disto-dorsal abdominal segments with latero-caudal angles showing distmct but not pronounced acute projections directed caudad. Supra-anal plate partly deformed. 122 Cerci fusiform; dorsal surface flat, showing the sutures of the joints weakly; apex acute; ventral surface of (thirteen) joints strongly convex with lateral margins narrowly but strongly cingulate, this greater for the external margins.
Femora heavily spined as characteristic of the genus. Caudal tibiae elongate, flattened, slender, unspecialized. Caudal tarsi very elongate; metatarsus slender, approximating the combined length of the succeeding joints, ventral surface with two rows of widely spaced minute spines, terminating distad at the moderately large globose pulvillus; succeeding three joints with ventral surfaces fully occupied by large pulvilli. Decidedly small arolia present between the bases of the tarsal claws.
Dorsal surface shining blackish with a ver>' slight brown tinge. Head the same color, ocellar spots ochraceous-buft"; a small spot on either cheek, entire clypeus, jaws and ventral half of labrum chestnut. Antennae in brief proximal portion shining blackish with a very slight brown tinge, remaining portions dull bay. Underparts, coxae and proximal portions of femora chestnut, becoming blackish chestnut distad on abdomen and distal portions of limbs. Pulvilli ochraceous-bufl".
Length of body, 49.2; length of head, 10.3; width of head, 9.2; width of interocular space, 5.9; length of pronotum, 13; width of pronotum, 19; exi)osed length of tegmen, 6.7; width of tcgmen, 4.8; width across mesonotum and tegmina, 20.7; ^ PVom the normal portion, apparent ly as in this sex of hioUeyi. greatest width of abdomen, 21.6; length of caudal tibia, 17.7; ventral length of caudal metatarsus, 6 millimeters.
The type of this interesting species is uniciue.